1. Field of the Invention
The present invention relates to a slot-line switching and limiting device which operates in the micro- wave-frequency range. This device operates in different modes according to whether the diodes which form part of the device are forward or reverse-biased. Depending on the mode of operation, this device attenuates the input microwave signal either partially (limiter) or totally (switch). In this device, the invention is essentially concerned with the circuit for compensating the reactive elements associated with each diode, that is to say its parasitic resistance, its self-inductance related to the connections and its reverse-bias capacitance.
2. Description of the Prior Art
Slot-lines (also known as slotted lines or finlines) are constituted by two metallization layers deposited on an insulating substrate such as quartz, alumina or a plastic substrate, a slot having a width of 100 to 200 microns being left between said layers. This circuit behaves as a waveguide within the frequency range of 18 to 200 GHz, for example. There are different ways of mounting one or a number of diodes in order to construct a circuit of this type in the form of an attenuator, a switch, or a limiter. The diodes employed are usually pin diodes or Schottky barrier diodes and are connected either by beam leads or wires. At microwave frequencies, these connections possess a self-inductance which has a predominant influence on the characteristics of the circuit.